Trinity Dam is an earth dam on the Trinity River that forms Trinity Lake near Weaverville, California. Trinity Lake was previously called Clair Engle Lake. The 538-foot (164 m) earthfill dam was built by the U.S. Bureau of Reclamation. Construction was completed in 1962. Trinity Lake has a capacity of 2,447,650 acre-feet (3.01913 km³), making it one of the largest reservoirs in California. Trinity Lake and Dam are part of the Central Valley Project, which harnesses the waters from the Sacramento River and San Joaquin River watersheds to irrigate the Central Valley. The area around the reservoir forms one of the three units of the Whiskeytown-Shasta-Trinity National Recreation Area.

Trinity Power Plant is a hydroelectric plant located at the base of the dam. The power plant has a capacity of 140 megawatts with two Francis turbines. The plant operates on a peaking basis.